<script>
import { isActive, hashRE, groupHeaders } from "../util";

export default {
  functional: true,

  props: ["item"],

  render(h, { parent: { $page, $site, $route }, props: { item } }) {
    // use custom active class matching logic
    // due to edge case of paths ending with / + hash
    const selfActive = isActive($route, item.path);
    // for sidebar: auto pages, a hash link should be active if one of its child
    // matches
    const active =
      item.type === "auto"
        ? selfActive ||
          item.children.some((c) =>
            isActive($route, item.basePath + "#" + c.slug)
          )
        : selfActive;
    const link = renderLink(h, item.path, item.title || item.path, active);
    const configDepth =
      item.depth !== undefined
        ? item.depth
        : $page.frontmatter.sidebarDepth != null
        ? $page.frontmatter.sidebarDepth
        : $site.themeConfig.sidebarDepth;
    const maxDepth = configDepth == null ? 1 : configDepth;
    const displayAllHeaders = !!$site.themeConfig.displayAllHeaders;
    if (item.type === "auto") {
      return [
        link,
        renderChildren(h, item.children, item.basePath, $route, maxDepth),
      ];
    } else if (
      (active || displayAllHeaders) &&
      item.headers &&
      !hashRE.test(item.path)
    ) {
      const children = groupHeaders(item.headers);
      return [link, renderChildren(h, children, item.path, $route, maxDepth)];
    } else {
      return link;
    }
  },
};

function renderLink(h, to, text, active) {
  return h(
    "router-link",
    {
      props: {
        to,
        activeClass: "",
        exactActiveClass: "",
      },
      class: {
        active,
        "sidebar-link": true,
      },
    },
    text
  );
}

function renderChildren(h, children, path, route, maxDepth, depth = 1) {
  if (!children || depth > maxDepth) return null;
  return h(
    "ul",
    { class: "sidebar-sub-headers" },
    children.map((c) => {
      const active = isActive(route, path + "#" + c.slug);
      return h("li", { class: "sidebar-sub-header" }, [
        renderLink(h, path + "#" + c.slug, c.title, active),
        renderChildren(h, c.children, path, route, maxDepth, depth + 1),
      ]);
    })
  );
}
</script>

<style lang="stylus">
@import '../styles/config.styl'

.sidebar .sidebar-sub-headers
  padding-left 1rem
  font-size 0.95em

a.sidebar-link
  font-weight 400
  display inline-block
  color $textColor
  border-left 0.25rem solid transparent
  padding 0.35rem 1rem 0.35rem 1.25rem
  line-height 1.4
  width: 100%
  box-sizing: border-box
  &:hover
    color $accentColor
  &.active
    font-weight 600
    color $accentColor
    border-left-color $accentColor
  .sidebar-group &
    padding-left 2rem
  .sidebar-sub-headers &
    padding-top 0.25rem
    padding-bottom 0.25rem
    border-left none
    &.active
      font-weight 500
</style>
